Lubricating oil



Patented Aug. 2, 1938 UNITED STATES PATENT OFFICE LUBBIOATING 01L Thomas G. Murphy, Franklin, Pa., assignor to L.

Sonncborn Sons, Inc., a corporation of Dela- This invention relates to lubricating oils.

An object of the invention is the provision of a lubricating oil which will not appreciably corrode metal, surfaces.

A lubricating oil derived from a Pennsylvania paraflin base crude and containing varying amounts of parafiinic constituents will corrode metal or alloy surfaces with which it comes in contact under temperature and pressure conditions obtaining in practice, and in many cases to such an extent, that the metal will, after a period of time, be deteriorated to a point where it must be replaced. The relatively short life of the metal renders its use expensive, and its replacement in many cases inconvenient.

1 I have discovered that the addition of from 0.05% to 0.5% of an alkali metal mahogany sulphonate will give to such Pennsylvania paraffin base lubricating oil anti-corrosive properties, and that metal or alloy surfaces coming in contact with such blended oil will not be corroded to the extent that has heretofore been experienced. 7

The alkali metal mahogany sulphonate is obtained by treating a lubricating oil fraction, for example, a fraction derived from a naphthenic base crude with sulphuric acid, preferably oleum. Such treatment yields an acid sludge, which contains water soluble green sulphonic acids, and an oil layer which contains oil soluble, mahog any sulphonic acids. The oil layer is separated from the acid sludge and treated with alkali, such as sodium or potassium hydroxide, whereupon sodium or potassium mahogany sulphonate is formed. The mahogany sulphonate can be extracted from such oil by treatment with an organic solvent, such as an aqueous alcoholic solution. Upon distillation of the alcoholic solution, the alkali metal mahogany sulphonate is recovered.

The lubricating oil to which the said sulphonates are added, is one derived from a Pennsylvania parafiin base crude, for example, a straight distillate containing varying amounts of paraffinic constituents or may consist predominantly of the same, It is common practice to blend straight distillates with small amounts bottoms, for example, an S. A. E. 20 commercialgrade of 90% straight distillate and 10% bottoms.-

The addition of from 0.05 to 0.5% of sodium or potassium mahogany sulphonates to a lubri-. eating oil derived from a Pennsylvania paraflin base crude and containing varying amounts of paraflinic constituents yields an oil which will not cause the corrosion normally associated with an oil not so treated, and metal or alloy surfaces which come in contact with my novel lubricant will experience a much longer life.

The above description is for purposes of illustration and not of limitation, and is not to be limited except by the appended claims in which I have endeavored to claim all inherent novelty.

metal mahogany sulphonate, said lubricating oil distillate being derived from a Pennsylvania paraflin base crude.

3. A lubricating oil composition consisting predominantly of a lubricating oil distillate containing parafilnic constituents, and from 0.05 to 0.5% of an alkali metal mahogany sulphonate, said lubricating oil distillate being derived from a Pennsylvania paraflin base crude. 1

4. A lubricating oil composition comprising a lubricating oil derived from a Pennsylvania paramp base crude, paraflinic matter, and from 0.05 to 0.5% of an alkali metal mahogany sulphonate.

5. The process of lubricating metal surfaces requiring lubrication while minimizing corrosion which comprises contacting such metal surfaces under lubricating conditions with a lubricating oil containing paraflinic constituents, to which has been added from 0.05 to 0.5% of an alkali metal mahogany sulphonate, said lubricating oil being derived from a Pennsylvania base crude.

THOMAS G. MURPHY. 

